1. Field of the Invention
This invention relates to an ophthalmologic measuring apparatus for measuring the condition of the blood flow on the fundus of an eye to be examined.
2. Related Background Art
Such an ophthalmologic measuring apparatus for measuring the condition of a blood flow on the fundus of an eye, as is known from International Laid-Open Patent WO 91/04705, etc., has heretofore been designed such that a laser beam is applied to the fundus of an eye to be examined and the reflected light thereof is photoelectrically detected and the velocity of the blood flow in the retinal tissue on the fundus of the eye to be examined is measured on the basis of this detection signal. This apparatus is constructed such that a speckle pattern, varying moment-by-moment with the movement of red blood cells in the retinal tissue is caught by an image sensor, whereby a speckle signal including the information of the blood flow velocity at each point in time is obtained as a time fluctuation of light intensity, and as a result, the distribution of the blood flow velocity in a predetermined area of the fundus of the eye is measured in terms of a relative value.
In the above-described example of the prior art, however, the blood flow velocity cannot be measured as an absolute value and the above-described apparatus is not always sufficient as an eye fundus blood flow meter.
In addition, the measurements by the methods which are capable of measuring only the relative blood flow value like those described above, depend on the individual 10 eye condition, so that doctor can not compare the result of one patient with another patient.